A combined thermographic analysis—Neural network methodology for eroded caves in a seawall

An application of an artificial neural network (ANN) combined with thermographic analysis for estimating the depth of eroded caves in a seawall is presented in this paper. A model experiment was first conducted in a sandbox using a thermographic device to detect the interior conditions of a structure from its temperature changes measured on the surface. The temperature difference calculated from the air temperature and the measured concrete surface point on a thermographic image was obtained for the neural network. Based on the laboratory data, an optimum ANN model for the estimation of the depth of eroded caves in a seawall was established by using four input factors: the site temperature, humidity, thermographic area, and the temperature difference. The model was verified using data from a seawall in Tainan City, Taiwan. From the results, it was found that the present ANN model efficiently estimates the depth of eroded caves in a seawall.     

基于地震约束的地质统计学建模方法研究

近年来,地质统计学在石油勘探开发中的应用日益广泛、深入,效果也越来越明显。基于地震约束的地质统计学建模技术是近几年发展起来的一项高新技术,是当今油藏描述的一个重要组成部分。它可以实现油气储层的精细描述和建模,降低储层建模中的不确定性。测井数据在垂向上具有很高的分辨率,地震数据在横向上能大范围地反映地质构造和砂体变化等特征。因此二者结合起来,发挥各自特点,取长补短,获得高精度的储层描述。笔者提出的方法,采用斯坦福大学的开源软件SGeMS中的多点统计算法模块模拟,将输入数据扩展为测井数据、训练图像及砂体概率。其中训练图像综合考虑地质分析中的砂体等厚图、地震反演结果切片、曲流河的沉积体系与物源方向,并可手工绘制得出。砂体概率数据通过地震数据反演获得。通过地震约束,可以大大降低只存在测井数据模拟时的井间区域不确定性。训练图像的加入,增加了地质学家对储层的地质认识。建模结果在反映目标体形态的基础上更加忠实于原始地质特征,对于井位稀少的区域效果尤其明显。     

Assessing the quality of data required to identify effective marine protected areas

This study aims to evaluate the effectiveness of currently available substrate data to designate marine reserves to meet conservation objectives. The case study site is Lyme Bay (approx. 2460 km²), in the western English Channel. An area of 240 km² in Lyme Bay was designated ‘closed to bottom dredging’ in July 2008 with the aim of protecting reefs which are an important habitat for Eunicella verrucosa (pink sea fan). The effects of using different substrate data resolution on the selection of sites to protect a range of biotopes using the Marxan package are determined. The effect of including a closed area on the efficiency of a marine reserve network is also investigated. Findings suggest that substrate data did not capture the biodiversity of the area and that using no data at all was equally effective. If low resolution data are all that are available then other options, such as expert opinion, or other data, such as activity use information could be used instead. Including a predefined closed area into the analysis led to an increase in area required to meet conservation goals using high resolution biotope data. It also increased the area of the reserve using the three substrate layers with no increase in protection for biotopes. This suggests that when designing networks of marine protected area sites, including current protected areas may be inefficient, resulting in larger areas being protected with no increased conservation of marine biodiversity. Policy makers must be prepared to adapt management in light of these findings and be aware of the shortcomings of the data available for use in marine conservation planning.     

机载激光测深精度外部检核方法

给出了单波束测深的原理,分析了单波束观测数据预处理模型,提出了采用单波束测深成果检核机载激光数据质量的技术方法,并以我国自行研制的机载激光测深系统为例,给出了该系统在某海区试验数据的外部检核结果.针对两种测深手段之间明显存在系统性偏差的问题,提出了以单波束测深成果为控制,对机载激光测深数据系统偏差进行校正和补偿的处理方...     

Intrusion of Kuroshio-Derived bottom cold water into Osaka Bay and its possible cause

The bottom layer in Osaka Bay was occupied in August from 1980 to 1995 by a water mass of relatively low temperature and rich in nutrients in comparison to previous and following decades. The relationship between Osaka Bay bottom temperature and Kuroshio axis location south of Kii Peninsula has been investigated using the dataset archived by Osaka Research Institute of Environment of Agriculture and Fisheries and axis-location data provided by Marine Information Research Center. The correlation between bottom temperature in the bay and Kuroshio-axis distance from Cape Shionomisaki indicates that the bottom temperature in the bay decreases when the Kuroshio axis is a long distance from the cape, and vice versa. To investigate why the temperature distribution depends on the axis location, composite temperature maps are depicted using summer temperature data from 1970 to 2005 archived in the Japan Oceanographic Data Center (JODC) after dividing all data into two groups with different axis locations. These temperature maps and temperature-salinity plots using the same JODC data suggest a scenario: cold water in the Kuroshio intermediate layer is first upwelled on the eastern side of the Kii Peninsula and thereafter moves westward as a coastal boundary current in the Kelvin wave sense of the Northern Hemisphere when the Kuroshio axis is located around 74-km distance from Cape Shionomisaki. This scenario is validated using internal Froude number maps depicted using the JODC-archived hydrographic data and geostrophic current fields. In addition, the reanalysis daily data provided by Japan Coastal Ocean Predictability Experiment are used for the validation.     

基于多水源分质供水技术的砣矶岛水资源优化配置

水资源紧缺问题制约砣矶岛社会经济发展。文章对砣矶岛水资源现状进行实地调研,主要包括地表水、地下水和海水淡化水的水量和水质;根据相关资料和发展规划,对砣矶岛水资源供需情况进行预测,得出2020年需水总量为48.33万m3,水资源缺口最高可达9.19万m3;通过总结目前岛上供水存在的问题,提出多水源分质供水的水资源优化配置方案,即增加9.19万m3/a的海水淡化工程以及污水处理和中水回用装置,生活用水采用地下水与淡化水的混合水,生产用水采用淡化水,生态用水采用地表水和回用水,同时建设水资源监视监测系统,提高水资源综合利用率。     

Data quality check procedures of an operational coastal ocean monitoring network

Field oceanographic and meteorological data are required for ocean engineering. In response to the requirement of field data, an operational coastal ocean monitoring network was established around Taiwan coast, including nine deep-water data buoys, one shallow-water pile station, 10 coastal weather stations and 10 tide stations. Data quality check procedures are necessary to ensure the accuracy of measurements. This paper presents the data quality check procedures on ocean wave data which includes automatic and manual check procedures. The checking criteria are derived using statistical theory in this paper. In addition, a sea-state-dependent algorithm is presented in this study in order to derive checking criteria of time-continuity check. It is showed to have better performance of picking up suspicious data than using fixed threshold process. This data quality check program is now used on the operational monitoring network.     

A dataset of continental river discharge based on JRA-55 for use in a global ocean circulation model

A dataset of historical river discharge into oceans was created using the CaMa-Flood global river routing model and adjusted runoff from the land component of JRA-55. The major rivers were well resolved with a 0.25° horizontal resolution. The total runoff on each drainage basin exhibits a distinctive bias on decadal time scales. The input runoff data were modified using 5-year low-pass-filtered multiplicative factors to fit the annual mean climatology and decadal variations in the reference dataset. The model incorporated data from 1958 to 2016. The yearly and seasonal variations of the major rivers are well represented by the model.     

Mapping benthic habitat in regions of gradational substrata: An automated approach utilising geophysical,geological, and biological relationships

The relationship between acoustic backscatter, sediment characteristics and benthic habitat is examined using high-resolution sidescan sonar data collected at the Loch Linnhe artificial reef site on the west coast of Scotland. The site is typical for the continental shelf of NW Europe, with a mix of seabed environments from muddy to coarse, stony substrata on a 10–100 m length scale. A sidescan sonar mosaic was produced and classified according to derived backscatter parameters (mean, median and standard deviation of the backscatter values) using an unsupervised classification procedure. The accuracy of the final classified map was assessed by comparison with a ground-truthing survey in which the biological habitat was derived from underwater video footage. The sidescan correctly predicted seabed surface characteristics of observed biological habitat with 78% accuracy. A second, and more challenging test of the acoustic data to correctly predict biological habitat was made by comparing it with data from 21 grab sampling stations. These stations were divided into three groups using multivariate statistical techniques based on their backscatter properties. Benthic assemblage structure was found to be significantly distinct between the high and low, and the medium and low backscatter stations. There was a low to moderate but significant correlation between the multivariate patterns of acoustic backscatter, benthic assemblage structure, and particle size distribution. The work shows that even in areas with subtle and gradational changes in substratum, the sidescan was able to predict biological community with an acceptable accuracy.     

Evaluation of the applicability of pier local scour formulae using laboratory and field data

The reliable estimation of the local scour depth at a bridge pier is essential for proper design and maintenance of bridge piers. Most local scour formulae have been developed based on the results of laboratory experiments. The formulae based on laboratory data do not often produce reasonable predictions for field piers because laboratory investigations are apt to oversimplify or ignore many of the complexities of the flow fields around the bridge piers. Validation of the formulae is necessary in order to ascertain which of the formulae are able to provide reasonable estimates of the local scour depth. In this study, six commonly cited formulae based on laboratory data or field data were selected for validation using 180 laboratory data sets gathered from the literature and 446 field data sets collected from four countries. The six formulae validated in this paper are the Colorado State University (CSU), Neill, Froehlich, Breuser, Laursen, and simplified Chinese formulae. Comparisons between the predicted and measured depths were performed using scour from the laboratory and field data. An artificial neural network technique was also applied in order to compare the tendencies between the field and laboratory data sets.     

A single point mooring spar buoy for measuring ocean waves

We made and set a spar buoy in September 1975 at Tsuyazaki for the purpose of developing the buoy system to acquire the oceanographical data. Motions of the buoy were also measured in terms of three components of acceleration, roll, and pitch. The buoy was removed from the site in May 1978.A method of eliminating influence of the buoy motion on the measured wave data was invented and examined by using the field data. It was found that the influence of the buoy motion on the wave data was so small that the amount of correcting the motion was negligible. In addition wave data obtained at the buoy were compared with those obtained at the fixed type platform, which was built in 1974 to get the reference data of wind, waves and currents. The agreement was found to be good. The performance of the buoy was as good as intended. Thus, it was shown that the buoy so far developed could be used as the platform for oceanographic research such as measuring wind and waves with higher precision.     

Biological assessment of rivers in the Manawatu‐Wanganui region of New Zealand using a predictive macroinvertebrate model

This study presents a river invertebrate and classification system (RIVPACS) type bioassessment methodology for the Manawatu‐Wanganui region of New Zealand. Aquatic macroinvertebrates and related physico‐chemical data were collected at 127 sites, with minimal human impacts (reference sites) in 2000. The reference sites were classified into five groups based on their macroinvertebrate data using TWINSPAN. These biotic groupings were then applied to their corresponding physico‐chemical data and discriminant functions were obtained to assign sites into the biotic groups using the physico‐chemical data. The discriminant functions correctly allocated 72% of the sites to the correct classification group using a jack‐knife validation. The probabilities from the discriminant functions were used to predict macroinvertebrate assemblages and these were compared with observed macroinvertebrate assemblages. The model was then used to assess the health of 29 test sites with known impacts. All test sites were assessed as impacted based on the 10th percentile of the reference data. To evaluate the temporal reliability of the model, data available for 11 sites sampled in 1997 and 2000 were run through the model. The results of this comparison showed little variation in O/E ratios over time and the two sites classed as impacted in 1997 were also classed as impacted in 2000.     

Classification of marine bioregions on the east coast of South Africa

Marine bioregional planning requires a meaningful classification and spatial delineation of the ocean environment using biological and physical characteristics. The relative inaccessibility of much of the ocean and the paucity of directly measured data spanning entire planning regions mean that surrogate data, such as satellite imagery, are frequently used to develop spatial classifications. However, due to a lack of appropriate biological data, these classifications often rely on abiotic variables, which act as surrogates for biodiversity. The aim of this study was to produce a fine-scale bioregional classification, using multivariate clustering, for the inshore and offshore marine environment off the east coast of South Africa, adjacent to the province of KwaZulu-Natal and out to the boundary of the exclusive economic zone (EEZ), 200 nautical miles offshore. We used remotely sensed data of sea surface temperature, chlorophyll a and turbidity, together with interpolated bathymetry and continental-slope data, as well as additional inshore data on sediments, seabed oxygen and bottom temperature. A multivariate k-means analysis was used to produce a fine-scale marine bioregionalisation, with three bioregions subdivided into 12 biozones. The offshore classification was primarily a pelagic bioregionalisation, whereas the inshore classification (on the continental shelf) was a coupled benthopelagic bioregionalisation, owing to the availability of benthic data for this area. The resulting classification was used as a base layer for a systematic conservation plan developed for the province, and provided the methods for subsequent planning conducted for the entire South African EEZ. Validation of the classification is currently being conducted in marine research programmes that are sampling benthic biota and habitats in a sampling design stratified according to the biozones delineated in this study.     

A Spectral Approach for Determining Altimeter Wind Speed Model Functions

We propose a new analytical algorithm for the estimation of wind speeds from altimeter data using the mean square slope of the ocean surface, which is obtained by integration of a widely accepted wind-wave spectrum including the gravity-capillary wave range. It indicates that the normalized radar cross section depends not only on the wind speed but also on the wave age. The wave state effect on the altimeter radar return becomes remarkable with increasing wind speed and cannot be neglected at high wind speeds. A relationship between wave age and nondimensional wave height based on buoy observational data is applied to compute the wave age using the significant wave height of ocean waves, which could be simultaneously obtained from altimeter data. Comparison with actual data shows that this new algorithm produces more reliable wind speeds than do empirical algorithms. This revised version was published online in July 2006 with corrections to the Cover Date.     

Improved description of global mixed-layer depth using Argo profiling floats

A global data set describing the gridded mixed-layer depth (MLD) in 10-day intervals was produced using high-quality Argo float data from 2001 to 2009. The characteristics and advantages provided by the new MLD data set are described here, including a comparison based on two different thresholds and using data sets of different vertical and temporal resolution. The MLD in the data set was estimated on the basis of a shallower depth of the iso-thermal layer (TLD) or iso-pycnal layer (PLD), calculated using the finite difference method. The MLD data are incorporated into 2° × 2° grid in the global ocean, including marginal seas. Also, two threshold values were used to examine differences in the MLD and its seasonal temporal variability. The characteristics and advantages of using the Argo 10-day intervals to determine the MLD were then confirmed by comparing those data with the station buoy daily means and the Argo monthly means. With respect to vertical and temporal resolutions, the Argo 10-day data has two distinct advantages: (1) improved representation of the MLD vertical change due to high vertical resolution, especially during periods of large MLD variability and (2) more detailed representation of the temporal change in MLD than achieved with the Argo monthly mean data, especially from winter to spring in mid and high latitudes. These advantages were maintained in the case of a larger threshold despite the fact that the MLD is rather deep and the detailed variation in its distribution differs depending on the season and location. This study also investigated the relative influence of TLD and PLD to the MLD calculation for each grid. Generally, the MLD is primarily determined based on the PLD at low and mid latitudes (TLD > PLD), whereas the TLD is more important at high latitudes, especially in winter (TLD < PLD). In the case of a larger threshold, the area of the larger PLD influence spreads polewards because of the greater effect of salinity in winter. Although there are some differences in the effect of temperature and salinity in estimations of the MLD, both are indispensable factors for the MLD estimations even at different thresholds.     

气象观测浮标短信查询及报警系统设计

介绍了基于手机短信的气象观测浮标数据库查询及报警系统的原理、硬件组成及软件开发。气象观测浮标通过北斗通讯将气象数据传输到指定计算机存储,系统实时监测定位信息、气象要素和接收短信命令,并将报警信息和命令响应通过短信发送至指定手机,达到实时掌握浮标状态的目的。在实际项目应用中,取代了人员值班,保证了报警实时性,达到了预期的效果。     

长序列北极海冰覆盖数据集对比分析

国家卫星气象中心使用2011年至今的风云三号卫星数据开发了一套基于Nasa Team2（NT2）算法的北极海冰密集度数据集,并可实时业务更新。将该数据集与其他国家不同机构业务运行并实时更新多种同类型数据集进行横向对比分析,其中包括:（1）美国冰雪中心基于Nasa Team（NT）算法以及SSM/I、SSMIS数据制作的1978年至今25 km分辨率全球极区海冰覆盖数据集;（2）美国冰雪中心基于Boot Strap（BS）算法以及SSM/I、SSMIS数据制作的1978年至今25 km分辨率全球极区海冰覆盖数据集;（3）美国NOAA基于多种卫星资料、地面观测数据以及海冰模型制作的2004年至今4 km分辨率北半球海冰覆盖数据集（IMS）。对比表明,上述数据集在北极地区不同的时空范围内存在一定的偏差。以分辨率较高的IMS数据集为基准,对其他3种长序列数据集进行初步评价,总体最大偏差超过100×104 km2,其中,NT2数据集过估较明显。经过与IMS数据集多年各月监测最大值的对比订正,NT2数据集过估情况得到改善。在此基础上的分析结果表明,NT、BS、NT2等3种数据集与IMS数据集相比,过估区域主要分布在海岸线附近,夏季过估比冬季更加明显,少估区域与算法、月份相关性明显,夏季少估面积也较冬季更大。NT、BS、NT2等3种数据集之中,NT2数据集与IMS数据集偏差最小,NT数据集次之,BS数据集与IMS数据集偏差最大。结果表明使用风云三号卫星数据的北极海冰覆盖数据集精度与国外3种同类型数据集相当。     

Optimizing interpolation of shoot density data from a Posidonia oceanica seagrass bed

A case study on the optimization of Posidonia oceanica density interpolation, using a data set from a large meadow at Porto Conte Bay (NW Sardinia, Italy), is presented. Ordinary point kriging, cokriging and a weighted average based on inverse square distance were used to interpolate density data measured in 36 sampling stations. The results obtained from different methods were then compared by means of a leave‐one‐out cross‐validation procedure. The scale at which interpolation was carried out was defined on the basis of the Hausdorff dimension of the variogram. Optimizing spatial scale and data points search strategy allowed obtaining more accurate density estimates independently of the interpolation method.     

An improved “benchmark” method for estimating particle settling velocities from time-series sediment trap fluxes

A new method, based on fitting Fourier series to time-series (TS) data from sediment traps, was developed to estimate the settling velocities (SVs) of sinking particles in the open ocean. This new method was applied to data from MedFlux, as well as from the US JGOFS NABE, EqPac, and ASPS studies. Fluxes of mass and of four chemical tracers, as well as the molar ratios of the latter, were plotted on logarithmic scales; Fourier series were then fit to these data. In each case we determined the most likely settling velocity using a likelihood-based nonlinear fitting algorithm. Variation among estimates using single tracers was significantly less than variation using tracer ratios; we therefore concluded that estimates based on single tracers are to be preferred to estimates based on tracer ratios. Our results also showed no obvious differences among SVs estimated using different single tracers. The best estimate of settling velocity using single-tracer fluxes with good temporal resolution (i.e. for sites with cup rotation times 8.5 days) is 205 m/d, with standard deviation 74 m/d. For MedFlux data alone (which have a resolution of 4–6 days), the estimate is 220±65 m/d. This latter value is within 10% of the estimate of average settling velocity (242±31 m/d) made using MedFlux IRS traps in “settling velocity” mode.     

Suspended matter in the surface layer of the southeastern Baltic from satellite data

The spatial and temporal variability of the concentration of suspended matter in the surface layer of the southeastern Baltic is analyzed using data from the satellite scanner MODIS-Aqua. The concentration of suspended matter was calculated by a regional algorithm developed on the basis of field data in the given region. The mean monthly distributions of the concentration of suspended matter from March to September 2003–2014 were calculated. The role of contributing factors is analyzed by using the data of the satellite scanner Landsat-8, with a spatial resolution of 30 m. Along with the whole area of studies, the seasonal and interannual variability of the concentration of suspended matter in different regions is considered. No meaningful trend for the average concentration of suspended matter over the considered period is shown.